My Noah is missing one of the yellow knobs from the front panel and its black spindle. Does anybody know where i might be able to get a replacement? I've already tried asking Sonic Core and they were unable to help me out.

If the spindle is gone, you will need to replace the potentiometer or encoder that was there. So you'll need to take it apart to replace that part, then adding a knob is easy. Post a picture of it here if you want confirmation before taking it apart.

The spindle is detachable from the encoder without major surgery. I've attached a photo of one of the three that I still have. The spindle would appear to be quite a bespoke part - the end where it splits into 3 attaches to the encoder - and is the more important part to source as regards getting the Noah fully functional.

I'll wade my way through the very extensive Digikey and Mouser catalogues when I get a bit of spare time this weekend. Hopefully they'll have something that will do the trick.

You will defn find those there. I absolutely wouldnt go the glue way unless there is no options left. This is such a standard part though. Ebay could also work but mouser or digikey also have nice knobs....but then again...ebay also.